Influence of twenty-five per cent human serum albumin on total and ionized calcium concentrations in vivo.

BACKGROUND: A inverse correlation has been found between changes in ionized calcium concentrations and the addition of albumin in vitro, which may explain adverse cardiovascular effects attributed to exogenous albumin in vivo. The purpose of this investigation was to determine the interaction (if any) between exogenous 25% albumin administration (100 ml given over < 30 min) and calcium concentrations in patients, all but one of whom were in an intensive care unit. RESULTS: There were no significant differences in the ionized calcium concentrations obtained before, at the end and 6 h after the administration of albumin (1.09 +/- 0.23, 1.06 +/- 0.22, 1.06 +/- 0.21 mmol/l, respectively). Similarly, there were no significant differences in the total calcium concentrations between these same time periods (2.03 +/- 0.18, 2.05 +/- 0.20, 2.08 +/- 0.23 mmol/l, respectively). CONCLUSIONS: In patients receiving infusions of 25% albumin, it appears that circulating calcium concentrations are well regulated by homeostatic mechanisms. Albumin infusions had no effect on calcium concentrations, although it is possible that temporary changes of questionable clinical importance may have occurred between measurement periods.

Falsely decreased total serum calcium concentration associated with iron dextran injection.

We cared for a patient in whom iron dextran administration interfered with the determination of total serum calcium concentration. An unexpected elevation in serum phosphorus concentration also occurred after the iron dextran infusion. A MEDLINE search from 1966 to present was conducted, and the manufacturer of the iron dextran was contacted for information related to these findings. Several drugs and diseases were found that may decrease serum calcium and increase phosphorus concentrations. We found one anecdotal citation of iron dextran interfering with serum calcium concentrations, but no reports of interference with serum phosphorus concentrations. Doses of iron dextran in excess of 250 mg may cause a false decrease in total calcium concentration more than 4 hours after the infusion is completed. A false increase in serum phosphorus concentrations after the infusion requires further investigation.

Characterization of cholecystokinin receptors on the human sphincter of Oddi.

BACKGROUND: The present in vitro study investigated the interaction between cholecystokinin (CCK) and receptors on human sphincter of Oddi tissue obtained from donated human livers that were being transplanted. METHODS: Radiolabeled ligands with cholecystokinin receptor specificity, autoradiography, and crystal scintillation counting were used to directly characterize cholecystokinin receptors on tissue sections. RESULTS: The binding of 125I-BH-CCK-8 to the tissue was saturable, specific, and dependent on time, pH, and temperature. Saturable binding of 125I-BH-CCK-8 was localized on the smooth muscle layer, and binding was inhibited only by cholecystokinin-related peptides. Computer analysis of 125I-BH-CCK-8 binding indicated the presence of two classes of binding sites, one with a high affinity and the other with a low affinity for CCK-8. CCK-8 caused relaxation (half-maximal concentration, 6 nmol/L) and carbachol caused contraction (half-maximal concentration, 10 nmol/L) of circular, cross-sectional strips of the tissue. Longitudinal strips were less responsive. The relative 125I-BH-CCK-8 binding inhibition potency of CCK-8 agreed closely with its relative ability to cause sphincter relaxation. Tetrodotoxin (1 mumol/L) and atropine (1 mumol/L) caused a rightward shift of the dose-response curve for CCK-8-stimulated sphincter relaxation. CONCLUSIONS: The present results indicate that cholecystokinin receptors on the human sphincter of Oddi are sulfate dependent and mediate sphincter relaxation.

Tachykinins mediate contraction of the human lower esophageal sphincter in vitro via activation of NK2 receptors.

The contractile response to natural tachykinins and selective peptide agonists for tachykinin receptors was studied in strips of circular smooth muscle of human lower esophageal sphincter in vitro. The effects of phosphoramidon, which inhibits neutral endopeptidase (EC.3.4.24.11) and of the non-peptide compounds, SR 48968 and CP-96,345, which selectively block NK1 and NK2 receptors, respectively, were also investigated. Substance P, neurokinin A and neurokinin B produced a concentration-dependent contractile response. The rank order of potency was neurokinin A > neurokinin B > substance P. Phosphoramidon (1 microM) potentiated the response to substance P without changing the order of potency of natural tachykinins. The NK2-selective agonist, ([ beta Ala8]neurokinin A-(4-10)), produced a concentration-dependent contraction. The NK1 ([Sar9,Met(O2)11]substance P, 1 microM) and NK3 ([MePhe7]neurokinin B, 1 microM) selective agonists, however, did not exert any contractile effect. The selective NK2 antagonist, SR 48968, potently inhibited in a concentration-dependent (10 nM-1 microM) manner the response to neurokinin A, without affecting the response to carbachol. The selective NK1 antagonist, CP-96,345 (1 microM), did not affect the response to neurokinin A. These results indicate that tachykinins contract the circular muscle of human lower esophageal sphincter, and that this effect is mediated by NK2 receptor stimulation. Moreover, a phosphoramidon-sensitive mechanism plays a role in the regulation of the response to substance P.

Revascularization technique for reduced-size liver transplantation for infants weighing less than 10 kg.

Reduced-size liver transplantation has been recognized as a powerful modality in alleviating the global donor shortage in pediatric liver transplantation. We describe, for the first time, a technique for revascularizing reduced-size grafts which has not been patterned after adult revascularization techniques. This revascularization method for reduced-size liver transplantation is particularly suitable for infants weighing < 10 kg. This technique differs from adult revascularization techniques in that the supraceliac aorta is always used as the origin for graft arterialization, and that the anastomoses are always performed in the following order: end-to-side donor celiac artery to supraceliac aorta anastomoses first, followed by the suprahepatic vena caval anastomoses, infrahepatic vena caval anastomoses, and then portal vein anastomoses. Hepatic artery thrombosis in infants weighing < 10 kg has occurred in 4 of 32 nonreduced versus 0 of 21 reduced transplantations (P = .05616, Z test, one tail). Adult revascularization was primarily used in the nonreduced group, whereas our proposed revascularization method was primarily used in the reduced group. We conclude that, for infants weighing < 10 kg receiving reduced grafts, this proposed technique should be used to decrease hepatic artery thrombosis.

The influence of portoenterostomy with stoma on morbidity in pediatric patients with biliary atresia undergoing orthotopic liver transplantation.

A portoenterostomy (PE) procedure for extrahepatic biliary atresia (EHBA) is sometimes performed with a stoma in an attempt to reduce the incidence of acute cholangitis. The purpose of this study was to determine if the presence of a stoma increased the complication rate of patients undergoing orthotopic liver transplantation (OLT) for EHBA. The medical records of 42 consecutive patients with EHBA who underwent primary OLT between October 1988 and October 1991 were retrospectively reviewed. Three patients were excluded, since their grafts were lost within 3 days of OLT. The remaining 39 patients were divided into three groups: no PE (n = 7), PE without stoma (n = 23), and PE with stoma (n = 9). The mean age of the whole group was 19.62 +/- 24.37 months, with a range of 5 to 132 months. Mean weight was 9.62 kg, with a range of 4.2 to 41 kg. Survival at 3 and 12 months as well as number of retransplantations were similar among the three groups. However, at the time of OLT increased morbidity was observed, consisting of increased operative time and number of reoperations, whether or not the stoma had been closed prior to OLT.

Characterization of cholecystokinin receptors on the human gallbladder.

BACKGROUND: Several studies examined in vivo and in vitro biologic activity of the human gallbladder in response to cholecystokinin (CCK). However, few studies have demonstrated directly the interaction of CCK with receptors on the human gallbladder, which is responsible for this biologic activity. METHODS: To characterize CCK receptors on human gallbladder tissue, gallbladders were removed from human donor grafts that were being used for liver transplantation. The gallbladders were rapidly frozen and sectioned for measurement of binding of 125I-Bolton-Hunter-labeled-CCK-8 and were cut into strips for in vitro bioassay. RESULTS: Binding of 125I-BH-CCK-8 to human gallbladder was saturable, specific, and dependent on time, pH, and temperature. The binding was inhibited only by cholecystokinin-related peptides including CCK-8 (IC50 10 +/- 1.0 nmol/L) (mean +/- SD), des(SO3) CCK-8 (IC50 0.9 +/- 0.2 mumol/L), and gastrin-17-I (IC50 9.0 +/- 2.0 mumol/L) or specific CCK receptor antagonist L-364,718. Computer analysis of binding of 125I-BH-CCK-8 to gallbladder tissue showed a single class of binding sites with high affinity for CCK-8. Autoradiography localized binding of 125I-BH-CCK-8 only to the smooth muscle layer of the gallbladder. In the bioassay des(SO3) CCK-8 (EC50 1.2 +/- 0.7 mumol/L) and gastrin-17-I (EC50 4.5 +/- 2.4 mumol/L) were 150- and 563-fold less potent than CCK-8 (EC50 8.0 +/- 2.2 nmol/L). The relative potencies of CCK agonists for inhibiting binding of 125I-BH-CCK-8 agreed closely with their relative potencies for causing gallbladder contraction. The dose-response curve for CCK-8 alone to induce gallbladder contraction was not significantly different from those caused by CCK-8 plus 1 mumol/L tetrodotoxin or 1 mumol/L atropine. CONCLUSIONS: These results characterized the CCK receptors on smooth muscle of human gallbladder as sulfate dependent and causing gallbladder contraction.

Variation in antibody reactivity to the hepatitis C virus by comparative immunoscreening and enzyme immunoassay.

The detection of antibody to the hepatitis C virus C100-3 antigen from the nonstructural region (NS3/NS4) of the viral genome was the first useful marker developed to detect past or potentially active infection with the hepatitis C virus. A systematic epitope survey of the nonstructural region has uncovered other immunogenic antigens. In order to assess the possible diagnostic utility of these antigens, their reactivity against a limited panel of sera from patients with chronic liver disease due to hepatitis C virus and other etiologies was tested. Antibody assays were performed using an immunoblot plaque assay and an enzyme-linked immunosorbent assay (ELISA). In a study of 16 C100-3-reactive individuals, all 16 patients were reactive using the plaque assay for the NS3 3' (409-1-1) and NS3 5' (C33u). In this same group of patients, antibodies by ELISA were reactive to NS3 3' in 12 of 16 patients (75%), NS3 5' in 15 of 16 patients (93%), and a capsid antigen (NC450) in 14 of 16 patients. In a group of five patients who were diagnosed with cryptogenic liver disease (C100-3 negative), 4 of 5 patients were reactive for antibody to all of the above epitopes. In a survey of 23 patients with other forms of chronic liver disease (nonviral liver disease, hepatitis B, alcoholic liver disease, cholestatic liver disease, and autoimmune hepatitis), only 1 of 23 patients was reactive for antibody to the C100-3 and 4 of 23 patients were reactive for antibodies to structural and nonstructural regions of the virus.(ABSTRACT TRUNCATED AT 250 WORDS)

Graft involvement by Legionella in a liver transplant recipient.

Legionella pneumophila, serogroup 1, was identified by direct immunofluorescence in the lung and liver graft from a 2 1/2-month-old infant who underwent orthotopic liver transplantation because of fulminant hepatic failure secondary to neonatal hepatitis. The patient died of respiratory failure owing to this infection 22 days after transplantation despite treatment with erythromycin lactobionate. To our knowledge, this represents the first reported case of hepatic infection with Legionella in liver transplant recipients.

Total abdominal evisceration: an en bloc technique for abdominal organ harvesting.

This paper describes an en bloc total abdominal evisceration (TAE) technique that has been used successfully in 81 consecutive multi-organ procurements in donors ranging from 2.5 to 85 kg. Preliminary dissection performed by the surgeon and physician's assistant averaged 30 to 45 minutes before aortic cross-clamping. Removal of all abdominal organs (liver, kidneys, pancreas, bowel) en bloc averaged 16 to 24 minutes after aortic cross-clamping, depending on the speed of the thoracic procurement. Organ grafts were preserved with the University of Wisconsin preservation solution. Total procurement time for the removal of the liver, pancreas, and kidneys averaged 1.5 to 2.25 hours. Because all vascular anomalies were easily recognized ex vivo, vascular reconstruction was possible, so that all donors could potentially provide for combined liver, pancreas, and kidney transplantation. In the TAE group, primary liver graft nonfunction was 1.2% (1/81 grafts), which is less than the non-TAE liver graft nonfunction rate of 7% (7/99 grafts); this is statistically significant (p less than 0.05). Also, the incidence of fresh frozen plasma support after liver transplantation in the TAE group (2/81 transplantations) was lower than the non-TAE group (9/99 transplantations) (p less than 0.05). The overall liver recipient survival rate was 87% (non-TAE; 78/94 recipients; TAE; 65/70 recipients). Kidney-graft initial function has been similar in both the TAE and non-TAE groups. All pancreas tissue was histologically normal, and extraction of viable islet cells (average, 3600 islets per gram pancreas) was possible with yields similar to standard pancreatic (average, 379 islets per gram pancreas) harvest techniques. Preliminary experience with combined liver and whole-organ pancreas transplantations has been encouraging, with immediate discontinuation of intraoperative insulin during transplantation.

Isolation of a neuropeptide-degrading carboxypeptidase from the human stomach.

The aim of this investigation was to isolate and characterize a neuropeptide-degrading carboxypeptidase from the muscular and mucosal layers of the human stomach. The carboxypeptidase was solubilized from membrane preparations of gastric muscle and mucosa using Triton X-100. The detergent-solubilized enzyme was purified to apparent electrophoretic homogeneity by affinity chromatography using lisinopril or potato carboxypeptidase inhibitor as an affinity ligand. The enzyme had an apparent molecular weight of 34,300 and was bound by concanavalin A and is thus a glycoprotein. The carboxypeptidase removed C-terminal leucine, phenylalanine, or tryosine residues from peptides including angiotensin I, [Leu5]enkephalin, kinetensin, neuromedin N, neurotensin, and xenopsin. It had an alkaline pH optimum and was inhibited by lisinopril, potato carboxypeptidase inhibitor, ethylenediaminetetraacetic acid, 1,10-phenanthroline, and 8-hydroxyquinoline. Immunoblotting indicated that the gastric carboxypeptidase cross-reacted with an antibody raised against a carboxypeptidase isolated from mast cells of human skin. The gastric carboxypeptidase released from gastric mast cells upon degranulation may act to degrade and inactivate neuropeptides in the stomach wall.

Liver transplantation. Experience with 100 cases.

Between March 1988 and November 1989, 100 liver transplants were performed on 90 patients at Pacific Presbyterian (now California Pacific) Medical Center in San Francisco. The immunosuppressive regimen was a combination of prophylactic Minnesota antilymphocyte globulin, cyclosporine, and low-dose corticosteroids. Rejections were treated with OKT3, a monoclonal antibody, or corticosteroids. Of the 100 transplants, 32 were done on 30 children, 18 of whom weighed less than 10 kg and 9 of whom received livers that had been surgically reduced in size to fit the recipient. The overall patient survival at 2 years was 85%. Of 100 liver transplants, treatment was given for 80 (80%) for at least 1 episode of rejection. At least 1 episode of serious infection occurred in 34 of the 60 adult patients and 25 of the 30 children. Of the entire group, 2% had hepatic artery thrombosis, and 12% had biliary complications that necessitated reoperation. The quality of life has been good, with a follow-up from 1 to almost 3 years (mean = 22 months). Comparing these data with those of other published series shows a decreased incidence of surgical complications and a lower rate of fungal and viral infections. We attribute this to the reduction of steroid dosage during convalescence without jeopardizing patient or graft survival.

The impact of liver reductions in pediatric liver transplantation.

Reduced-size liver transplantation (RSLT) in children was introduced to alleviate a shortage of small-organ donors. The impact of RSLT on the waiting time for an organ and on morbidity and mortality was investigated. Between March 25, 1988, and August 11, 1990, 61 hepatic transplantations were performed in 55 children at the Pacific Transplant Institute in San Francisco, Calif. Full-size liver transplantation was performed in 41 cases and RSLT in 20 cases. The overall 30-month actuarial patient and graft survival rates were 89% and 73%, respectively. A comparison between full-size liver transplantation and RSLT showed no difference in patient and graft survival, reoperations, infections, or rejection. Benefits of RSLT were an increase in the donor pool size, a decrease in waiting time for a suitable donor, and a decrease in the rate of arterial thrombosis. The main morbidity of RSLT was an increase in perioperative blood requirement. We conclude that RSLT offers small children with end-stage liver disease a chance for long-term survival.

Successful 20-hour rat liver preservation with chlorpromazine in sodium lactobionate sucrose solution.

We investigated the effect of the addition of chlorpromazine to a new, simplified organ preservation solution, sodium lactobionate sucrose (SLS), for 20-hour hypothermic rat liver preservation. Survival beyond 7 days after orthotopic transplantation of the stored liver was eight of eight rats in control groups (immediate transplantation, less than 1-hour preservation), one of 14 rats with the University of Wisconsin (UW) solution, four of 14 rats with SLS, seven of eight rats with SLS + chlorpromazine, 1 mg/L, and seven of eight rats with SLS + chlorpromazine, 10 mg/L. The differences is survival between UW and SLS and between SLS and SLS + chlorpromazine were significant (p less than 0.05). Lactic dehydrogenase levels in the effluent after reflushing through the portal vein at the time of transplantation were 145 +/- 20 IU/L (mean +/- SEM) in the controls, 525 +/- 78 IU/L in UW, 492 +/- 44 IU/L in SLS, 290 +/- 39 IU/L in SLS + chlorpromazine, 1 mg/L, 290 +/- 11 IU/L in SLS + chlorpromazine, 10 mg/L. The values for the SLS + chlorpromazine were significantly lower than for SLS and UW (p less than 0.05). The pH of the effluent was 7.10 +/- 0.10 in controls, 6.42 +/- 0.12 in UW, 6.64 +/- 0.18 in SLS, and 7.07 +/- 0.02 in SLS + chlorpromazine, 1 mg/L and 10 mg/L. The pH drop was significantly greater in the groups without chlorpromazine (p less than 0.01). This study shows that superior rat liver preservation was achieved with a simplified lactobionate solution containing sodium as the principal cation, sucrose in place of raffinose, and omitting the colloid and several of the other UW components. The addition of low concentrations of chlorpromazine further enhanced the effectiveness of this solution, without the need for donor pretreatment.